Several processes for the separation of a desired material from a mixture comprising this desired material and, in addition, undesired materials are described in the prior art.
WO 02/066168 A1 relates to a process for separating ores from mixtures comprising these, in which suspensions or slurries of these mixtures are treated with particles which are magnetic and/or capable of floating and/or reporting to the froth phase of flotation in aqueous solutions. After addition of the magnetic particles and/or particles capable of floating, a magnetic field is applied so that the agglomerates are separated from the mixture. However, the extent to which the magnetic particles are bound to the ore and the strength of the bond is not sufficient for the process to be carried out with a satisfactorily high yield and effectiveness.
U.S. Pat. No. 4,657,666 discloses a process for the enrichment of ore minerals, in which the ore mineral present in the gangue is treated with magnetic particles, as a result of which agglomerates are formed due to hydrophobic interactions. The magnetic particles are hydrophobized on the surface by treatment with hydrophobic compounds, so that agglomeration to the ore minerals occurs. The agglomerates are then separated off from the mixture by means of a magnetic field. It is disclosed that the ores are treated with a surface-activating solution of sodium ethylxanthate, which may also be called sodium ethylxanthogenate, before the magnetic particle is added. In this process, separation of ore minerals and magnetic particle is effected by the destruction of the surface-activating substance which has been applied in the form of the surface-activating solution to the ore.
WO 2010/100180 A1 relates to an agglomerate of at least one particle P which is hydrophobized on the surface with at least one first surface-active substance and at least one magnetic particle MP which is hydrophobized on the surface with at least one second surface-active substance, a process for producing these agglomerates and the use of the agglomerates for separating a particle P from mixtures comprising these particles P and further components.
WO 2010/097361 A1 relates to a process for separating at least one first material from a mixture comprising this at least one first material, at least one second material and at least one third material, wherein the mixture to be treated is firstly brought into contact with at least one hydrocarbon in an amount of from 0.01 to 0.4% by weight, based on the sum of mixture and at least one hydrocarbon, this mixture is further brought into contact with at least one hydrophobic magnetic particle so that the magnetic particle and the at least one first material agglomerate and this agglomerate is separated from the at least one second material and the at least one third material by application of a magnetic field and, if appropriate, the at least one first material is subsequently separated, preferably quantitatively, from the magnetic particle, with the magnetic particle preferably being able to be recirculated to the process.
WO 2010/066770 A1 discloses a process for separating at least one first material from a mixture comprising this at least one first material in an amount of from 0.001 to 1.0% by weight, based on the total mixture, and at least one second material, in which the first material is firstly brought into contact with a surface-active substance in order to hydrophobize it, i.e. to render it hydrophobic, this mixture is then brought into contact with at least one magnetic particle so that the magnetic particle and the hydrophobized first material agglomerate and this agglomerate is separated from the at least one second material by application of a magnetic field and the at least one first material is then preferably quantitatively separated from the magnetic particle, with the magnetic particle preferably being able to be recirculated to the process.
WO 2010/007157 A1 discloses a process for separating at least one first material from a mixture comprising this at least one first material and at least one second material, in which the mixture to be separated is firstly brought into contact with at least one selective hydrophobizing agent so that an adduct is formed from the at least one hydrophobizing agent and the at least one first material, this adduct is then brought into contact with at least one magnetic particle functionalized on the surface with at least one polymeric compound having an LOST (lower critical solution temperature) at a temperature at which the polymeric compound has hydrophobic character so that the adduct and the at least one functionalized magnetic particle agglomerate, this agglomerate is separated off by application of a magnetic field and the agglomerate is subsequently dissociated by setting a temperature at which the polymeric compound has hydrophilic character.
WO 2010/007075 A1 relates to a process for separating at least one first material from a mixture comprising this at least one first material and at least one second material, in which the mixture to be separated is brought into contact with at least one bifunctional compound and at least one magnetic particle so that an adduct is formed from the at least one first material, the at least one bifunctional compound and the at least one magnetic particle, this adduct is dispersed in a suitable dispersion medium, the adduct is separated off by application of a magnetic field and the adduct which has been separated off is, if appropriate, disassociated by suitable measures in order to obtain the at least one first material.
WO 2009/065802 A2 relates to a process for separating at least one first material from a mixture comprising this at least one first material and at least one second material, in which a suspension of the mixture comprising at least one first material and at least one second material and at least one magnetic particle in a suitable suspension medium is firstly produced, the pH of this suspension is set to a value at which the at least one first material and the at least one magnetic particle bear opposite surface charges so that these agglomerate, the agglomerates obtained in this way are separated off by application of a magnetic field gradient and the agglomerates which has been separated off are dissociated by setting the pH to a value at which the at least one first material and the at least one magnetic particle bear the same surface charges in order to obtain the at least one first material separately.
US 20120132032 A1 discloses a process for the separation of at least one metal from a slag, comprising that at least one metal and further components, comprising at least step (A) grinding the slag, (B) if appropriate, contacting the ground slag of step (A) with at least one surface-active substance and/or at least one magnetic particle, if appropriate in the presence of at least one dispersant, resulting in formation of agglomerates of the at least one metal and the at least one magnetic particle, (C) if appropriate, addition of at least one dispersant to the mixture obtained in step (B) to give a dispersion having a suitable concentration, and (D) separation of the agglomerates from the mixture of step (B) or (C) by application of a magnetic field, and to the use of at least one magnetic particle for the separation of slag. The use of magnetic particles can be optional if the slag contains magnetically separable, valuable-containing particles.
The processes for separating a desired valuable matter containing material from a mixture comprising this desired material and further undesired materials that are disclosed in the prior art can still be improved in respect of the separation efficiency, the yield of desired valuable matter and/or in respect of the grade of the obtained desired valuable material in agglomerates comprising the desired valuable matter containing material. An improvement of this separation process will further increase the efficiency of the whole valuable matter recovery process chain. For example, while increasing the separation efficiency of the process of the invention, smaller or less apparatuses for the separation can be used, so that the overall space-time yield of the valuable matter recovery process can be increased.
Further, the presence of disturbing and potentially toxic compounds, such as chromium or chromium comprising minerals, may also be undesired and for example may increase the risk of contamination of the personal handling the material. It is also known that chromium comprising minerals increase the melting point and thus lead to melt crystallization in a smelter oven affording high additional processing costs.
It is therefore an object of the present invention to provide a process for the separation of at least one valuable matter containing material from a dispersion that also comprises further undesired materials. Furthermore, it is an object of the present invention to provide a process which makes it possible to separate off the at least one valuable matter containing material efficiently. Furthermore, it is an object of the present invention to improve the yield of said at least one valuable matter containing material in said separation process.
It is also an object to provide a process for separating at least one hydrophobic or hydrophobized material from a dispersion comprising the at least one hydrophobic or hydrophobized material and at least one second material.